Drainage basin key terms

Evapotranspiration:

the total amount of moisture removed by evaporation and transpiration from a vegetated land surface. transpiration is the process by which water is lost from a plant  through the stomata in its leaves.

infiltration:

the passage of water into the soil. Infiltration takes place relatively quickly at the beginning of the storm, but as the soil becomes more saturated the infiltration rate falls rapidly. soils can affect the amount of water they hold - eg sandy soils let more through than clay soils.

Interception:

the process by which raindrops are prevented from directly reaching the soil surface. Leaves, stems and branches on tress and herbaceous plants / grasses growing close to the surface intercept water. Evaporation removes some of this moisture and so does not flow as runoff.